Folding pen



FIG. 1 is a front elevation view thereof;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a left side elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a front elevation view showing a folded status thereof;

FIG. 8 is a front-top perspective view thereof;

FIG. 9 is a rear-top perspective view thereof;

FIG. 10 is a front-bottom perspective view thereof; and,

FIG. 11 is a rear-bottom perspective view thereof. 

CLAIM The ornamental design for a folding pen, as shown and described. 